Nicholas benardos



(No Model.) 2 Sheets-Sheet 1.

N. BENARDOS.

RHEOSTAT.

Patented Apr. 16, 1889.

N PETERS PhulmLxhugmphsn Washinglen. n C

2 Sheets-Sheet 2.

Patented Apr. 16, 1889.

N, PETERS. Pfimta-Lilbographlr washmgim (No Model.)

N. BENARDOS.

RHEOSTAT.

UNITED STATES PATENT OFFICE.

NICHOLAS BENARDOS, OF ST. PETERSBURG, RUSSIA.

RH EOSTAT.

SPECIFICATION forming part of Letters Patent No. 401,405, dated April 16, 1889.

Application filed January '7, 1888. Renewed March 9, 1889. Serial No. 302,745. (No model.) Patented in Belgium December 19, 1887, No. 79,974; in France December 19,1887,No.187,682; in England December 21,1887,N0.17,585; in Italy Decemher 31, 1887, XLV, 385, and in Austria-Hungary March 26, 1888, N0. 805,

T0 all whom it may concern.-

Be it known that I, NICHOLAS BENARDOS, gentleman, residing at St. Petersburg, Russia, a subject of the Emperor of Russia, have invented certain new and useful Improvements in Rheostats, (for which I have obtained Letters Patent in France, dated December 19, 1887, No. 187,682; in Belgium, dated December 19, 1887, No. 79,974; in England, dated December 21,1887, No.17,585; in Italy, dated December 31, 1887, volume XLV, No. 385; in Austria-Hungary, dated March 26, 1888, tome 3S, folio 857, and tome XXII, No. 805, and that I have made application for patent in Russia under date of August 21,1887;) and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanyingdrawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The invention relates to rheostats or instruments for regulating the strength of electric currents, and has for its object to simplify the construction of these instruments, to provide means for readily regulating the resistance of the conductor to the passage of the electric current, and to provide means for connecting a plurality of such instruments in series, either for tension or quantity. These objects I attain by dispensing with the ordinary resistance-coils and employing in their stead an electric conductor or conducting material capable of being compressed or compacted to regulate the resistance to be offered to the passage of an electric current, by providing electrical connections so constructed that the instruments may be connected, either for tension or quantity, by the interposition of pegs or pins in a manner similar to that in general use with commutators or switchboards in telegraphic or telephonic systems.

To these ends the invention consists in a conductor for rheostats, consisting of a mate rial capable of being compressed or compacted to increase or decrease its resistance to the passage of an electric current, of a holder for said material, and suitable appliances for more or less compressing or compacting the same within the holder, substantially as hereinafter fully described and claimed.

The invention further consists in so arranging the supports for the rheostat and connecting the same with the conducting material that a plurality of instruments may be connected, either for tension or quantity, by the interposition of a peg or pin. between said supports, substantially as hereinafter described and claimed.

The invention further consists in certain structural features and in combinations of parts, substantially as hereinafter described and claimed.

In the accompanying drawings, Figure l is a top plan view of a group of rheostat-s embodying my invention, the inclosing-casing being partly broken away. Fig. 2 is an elevation showing one of the rheostats in transverse section, a portion of the inclosing-casing' being also broken away. Fig. 3 is a section taken on line :c a: of Fig. 1. Fig. 4 is a sectional view of a portion ofthe rheostat, illustrating a slightly-modified construction; and Fig. 5 shows by a face and edge View a key for manipulating the cylinder-heads or heads of the rheostat.

I11 the construction of my improved rheostat I employ a holder or receiver of cylindrical or other form in cross-section, which holder may be made of any desired material. In Figs. 1, 2, and 3 I have shown a rheostat in which the holder is made of metal and of cylindrical form in cross-section. The holder or cylinder A is screw-threaded interiorly at both ends for the reception of the heads a thereof, which are conveniently provided with holes a" or sockets for the reception of the pins It of a key, K, by means of which the said heads a are screwed in or out 1 of the cylinder.

\Vhen the inclosing casing or holder of the rheostat is made of metal, its inner surfaces are coated or lined with a suitable non-conductive material-such as rubber or other like materialas shown at c The cylinder-heads are provided with an axial opening for the passage supporting the rheostat and connecting the core or filling with the source of electricity and with the line, or for connecting a plurality of rheostats for tension or quantity and with the source of electricity and line. To these ends the piston-rods are supported in forked bearings 0, formed in the upper end of the vertical branch of an angular T-shaped strap, bar, or band, C, the horizontal branch ofwhich constitutes the foot of the support and is secured to a base-board, B, made of a non-conductive material, by means of screws 0 In the ends of the foot 0 of the supportare formed semi-cylindrical recesses, so that when a plurality of rheostats are employed they may be connected in series bymeans of a peg or pin, D, inserted into the semi-cylindrical recesses formed in the adjacent ends of the feet 0 of the supports C, the base-board B being provided with suitable holes or sockets for said pegs or pins. A strap or bar or band, 0', serves to connect the supports at opposite ends of the rheostats, also by the interposition of pins or pegs D, as shown.

. It is obvious that by moving the nut '12 on the piston-rod 19 away from the forked bearing the piston may be readily forced into the cylinder when it is desired to compress or compact the conductive material therein, after which both nuts n' and n are moved back in contact with the forked bearing 0.

The means for compacting or compressing the conductive material within the cylinder to adjust the resistance to be offered thereby to the passage of the electric current may be varied as well as the means for manipulating the compacting devices. For instance, the piston-rods p may be made to work in screwthreaded openings in the cylinder-heads for manipulation with a key, or the bearings for said rods may be screw-threaded for the purpose. The pistons may be dispensed with altogether, and the cylinder-heads a may be made to perform the function of pistons, as shown in Fig. 4-a construction admirably suited to holders made of a non-conductive material. The cylinder-heads may be made to slide into instead of screw into the cylinder or into a holder of the other form in crosssection, suitable means being provided to lock them into their adjusted position.

One of the pistons may be dispensed with, as will be readily understood, though better results are obtained by the use of two pistons operating in reverse directions upon the compressible conductive material, which is more uniformly compressed or compacted by means of two such pistons.

The rheostats need not necessarily be supported as described, as they may be supported in any other manner; yet the construction and arrangement of these means, in conj unction with utilizing the supports as a means for electrically connecting the rheostats with one another and with the line and source of electricity, is a very simple and convenient As a means of resistance to the passage of the electric current through the rheostat, any suitable conductive material capable of being compressed or compacted may be employed. Itwill be found that carbon in a comminuted formas, for instance, in granular form mixed with pulverized graphiteconstitutes an excellent compressible conductive material, 01; or the above materials and pulverized carbon may be employed.

It will be seen that by means of the described construction of rheostat the currents may be regulated with great facility, while the cost of such instruments is much less than that of like instruments as now constructed.

In practice the instrument or instruments is or are inclosed in a casing, E, for obvious purposes;

Having described my invention, what I claim is 1. A rheostat comprising a holder or receiver, a conductive material capable of being compressed or compacted, and an adjust able metallic follower or piston arranged to operate upon said material, in combination with a support for the rheostat, consisting of a metallic band, bar, or strap of T shape, provided with a bearing for the piston-rod in its vertical branch, and with recesses in the outer edges of the horizontal branch or branches, substantially as described, for the purposes set forth.

2. A rheostat comprising a holder .or receiver of non-conductive material, a compressible conductive material contained in said cylinder, and a metallic piston or pistons arranged to operate upon said material, in combination with a support for the rheostat in electrical connection with the compressible conductive material, said support consisting of a band or bar of T shape, the horizontal arms whereof are provided with a notch or recess in their outer ends, substantially as and for the purposes specified.

3. The combination, with a plurality of rheostats, each comprising a holder or receiver of non-conductive material, a compressible conductive material contained in said holder, a piston or pistons arranged to operate upon said material, and a T-shaped metallic support, the foot or horizontal arms of which are provided in their outer ends with a notch or recess, of the pins D, the connecting band or strap 0', and a suitable supporting-bar, upon which said rheostats are arranged side by side, substantially as shown and described, for the purposes specified.

In testimony whereof I affix my signature in presence of two witnesses.

NICHOLAS BENARDOS.

Witnesses:

N. TSCHEKALOFF, L. Voss. 

